Variable signal transmitting station



Dec. 12', 1950 Filed April 19, 1947 C. E. BEACH VARIABLE SIGNAL TRANSMITTING STATION 2 Sheets-Sheet 1 INVENTOR.

Dec. 12, 1950 c. E. BEACH 2,533,344

VARIABLE SIGNAL TRANSMITTING STATION Filed April 19, 1947 251169128-311661; 2

FIG. 13

IN V EN TOR.

?atented Dec. 12, 1959 Clarence 1E. Beach, Binghamton, N. Y.

Application April 19, 1947,.Serial No. 742,722

I 10 Claims.- 1

This invention relates to variahlesian'al transmitting stations, and is particularly suited for embodiment in stations of the type exemplified by so-called municipal fire alarm boxes.

Each such fire alarm box ordinarily consists of an outer case comprising a door or cover and'containing an inner case in which mechanism is mounted for formulating a predetermined code signal which characterizes the locality where the box is installed (hereinafter sometimes referred to as location-code): together with a manual key for sending special calls, and a tap bell or other signal'manifester.

The signal keys which have been provided in fire alarm boxes are utilized for sending various special signals and calls, including so-called fireout signals and test signals; but the most importantoccasion for using such keys arises when a department ofiicer at a fire decides that added assistance should be summoned.

In other Words, certain of the calls for which such keys are intended are of even greater importance than the locality-indicating callswhich are initiated by ordinary pulling of a box by a member of the general public.

It is, therefore, an important object of this invention to provide means for causing the formulation of variable special calls, which means will serve to safeguard such calls during various faulty conditionings of the associated circuit, to an ex- 5 tent as great as that obtained by location-codetransmitting mechanisms having characteristics such as contemplated by my Patent No. 1,999,859, granted April 30, 1935.

It is another object to provide means for for- 5 a normally closed main signaling circuit and a" normally isolated branch circuit, a signalingsender means, as for example a finger hold dial which is manually operable for selectively effecting formulation of diverse groups of code signaling impulses, the sender means comprising impulse formulating contacts having connections with the main and branch circuits, spring jacks serially connected in t e main circuit, a cover mounted on the box and positionable for obf M structingm'a'nual' actuation of t e ignal send ingmean's, a switching means operably connected with the main and branch circuits, means connected to said cover'fo actuating the" switching means to different positions, the connections between the respective circuits and the switching means being effective for including either said contacts or said jacks in said branch circuit but onlywhen said cover is in an unobstructiveposition with respect to said signal sender means,

the switching means also being'effective when said cover is in an obstructive position with respect to the signal sender means to provide in connection with a suitable conductor e. si. tin

' the main circuit around the formulating contacts.

obstructive position which circuit change is of a character such that if a signal is in course of' formulation in the sender circuit (as from some other sender) at the time when the cover is Withdrawn, a conditoning of such circuit will be established to cause susp nsion of the formulation of the signal of the distant transmitter, in

at least a portion of the main sender circuit, and

Will effect reservation of at least that portion of the circuit for the signal of the associated sender.

Additional objects and advantages of this invention will become apparent to those skilled in this art by a study of the following description and claims, taken in connection with the drawings showing illustrative embodiments of the invention, wherein Figure 1 is a fragmentary elevation of a wellknown type of fire alarm box transmitting station, with an embodiment o thisinvention applied thereto, and showing the hinged cover over the variable signal impulse sender in-closed position;

Fig. 2 is an elevation of the parts shown in Fig. l, with the hinged cover in open" position;

Fig. 3 is a fragmentary elevation of the inner side of the inner door of Figs. 1 and 2, with a portion of the rear protective cover Or can brokenaway to show an arrangement of circuit conditioning contacts suited for accomplishing certain functional results;

Fig. 4 is a cross-sectional view of the inner door of Figs. 1, 2, and 3, taken approximately along the line 4-4 of Fig. 3, showing the hinged cover in closed position, and indicating the resultant positioning of the conditioning contact mechanism;

Fig. 5 is a view similar to Fig. 4, showing the hinged cover open, with resultant change in the positioning of the conditioning contact mechanism;

Fig. 6 is a schematic diagram of one of the more simple arrangements of current paths between parts such as are shown in Figs. 3, 4, and 5, in association with a signaling circuit suitable for response thereto;

Figs. 7 through 14 show a modified arrangement of contacts, and operating mechanism therefor, which arrangement is suited for accomplishment of results diverse from those obtained by use of the arrangement shown in Figs. 3 through 6; and in which Fig. '7 is a fragmentary elevation, similar to that of Fi 3;

Figs. 8, 9 and 16 are cross-sectional views of the inner door of 7, taken approximately along the line 8-8 of Fig. 7, and, respectively, showing the hinged cover fully closed, partially and fully open, and indicating the resultant positionings of the conditioning contact mechanism;

Figs. 11, 12, and 13 diagrammatically indicate the positionings of the contact cylinder with relation to the conditioning contacts of Figs. 8, 9, and 19, respectively; and

Fig. 14 is a schematic diagram of an arrange ment of current paths between parts such as shown in Figs. '7, 8, 9, 10, ll, 12, and 13, for p10- ducing results differing from those obtainable by the arrangement shown by Fig. 6.

Description, Figs. 1-6

Referring to Figs. 1, 2, and 3, portions of the outer housing of a well-known type of flre alarm box are indicated at 2|, 2i, together with an edge view of the open outer door 23.

The inner case 25 has the inner door El secured thereto by hinges, such as 3!. Said door is provided with an operating knob 29, secured thereto by the screw 33.

An opening 33 is provided for a starting or pull handle 35, which is associated in a usual manner with a suitable location code signaling mechanism (not shown).

A cover member ll is secured to the inner door 2'? by the hinges l3. Said cover has a handle 65, also a boss l'i which may be engaged by a similar boss 8 carried by the outer door 23 (see Fig. l) for at times assuring obstructive positioning of said cover as will be hereinafter more fully explained.

A variable signal impulse sender is carried by the door 27. This sender comprises a finger hold dial 5! and a finger stop 53, together with contacts operable responsive thereto for governing interconnection between three conductors in a manner which will presently be explained in greater detail. One arrangement of the contacts operable responsive to said dial 5| is generally indicated by dotted lines at 55 in Fig. 3, and is shown in greater detail in Fig. 6 as comprising the contacts 8!, 93 and 95 and the actuator 9?, all of which will be hereinafter more fully described: Another arrangement of such contacts is generally indicated by dotted lines at 55 in F Fig. '7, and is shown in greater detail in Fig. 14 as comprising the contacts 9|, 93 and 95 and the actuator 9?.

Various well-known types of impulse sender mechanisms may be employed. Inasmuch as the details of such mechanisms iorm no part of this invention, none of such details are indicated in the drawings, other than the conventional dial ii, the finger stop 53, and the contacts 55 or 55; together with a rear cover or cap 55? for enclosing suitable operating mechanism. Said dial is so situated with reference to the hinged cover ll as to be rendered inaccessible when said cover is in closed position.

A cam comprising the portions 65 and 65 moves with the cover member it for actuating a lever 63. The portion 6% of said cam has a slot 67 formed therein (see dotted lines, Figs. 2, 3, 4, and 5). A wall 69 at one side of said slot provides a continuation of the periphery of the cam 65, and the other side of said slot provides an internal cam surface 1 I.

A roller 73, carried at one end of said lever 83, is engaged by the cam surfaces 59 and El. The contact cylinder "55 is carried by the other end of the lever 53, but is insulated therefrom.

Said cylinder ?5, together with flexible contacts l1, Ti and E9, 19, provide circuit conditioning contacts suited for use in systems in which it is desired to obtain operating results which will be hereinafter more fully set forth.

The flexible contacts ll, :7 are so positioned that the free ends thereof will be engaged by the cylinder '.'5 when the arm 83 is positioned by engagement of the roller 13 by the cam portion [55 or the external cam wall 69 which is adjacent thereto (see dotted position a in Fig. 6) and the flexible contacts 19, 73 are so positioned that said cylinder 75 will engage the free ends thereof when the lever 63 is positioned by engagement of said roller 73 by the internal cam surface ll when the cover l! is fully closed (see dotted position c in Fig. 6).

The parts are so proportioned that said cylinder 75 may be positioned intermediate said contacts ii and is (see dotted position b in Fig. 6), and so that when said cylinder 1'5 is in position 0 (where it engages the contacts iii, 79, resultant from full closure of the cover 5!) the clearance between said cylinder and said contacts ll, T! will be such that the path of any discharge of lightning or other static current from one to the other of said contacts 11, Te will be unlikely to include said cylinder 75.

From the foregoing, it will be seen that a current path is provided for inclusion in the external circuit, which path serially connects the jacks which are generally indicated at 8! and 83 with the formulating contacts 9! and 53, respectively.

The catch 99 which cooperates with a suitably positioned depression in a surface of the cam 6i, provides means for indicating to the user when the cover 4| is positioned for causing placement of the cylinder 15 out of engagement with both the contacts Tl, TI and the contacts l3, 79 (see dotted position b in Fig. 6).

One of the more simple applications of this invention is diagrammatically shown in Fig. 6. For purposes of illustration, the contacts thus far described are here shown in association with a circuit arranged in accordance with my Patent No. 2,034,017, dated March 17, 1936, for Multiconductor Signaling System.

The normal battery NB, the line signal manifestingv ground battery GB, the; instruments: LI,v GI and EI, and the rectifiers IR'- and, IR cor.- respond with instrumentalitiessimilarly; designated in said patent; to which referenceishad; The line signal manifestingv instruments LI, GI. and EI, may be of various types well-knownto persons skilled in this art;v for example, suchas; that disclosed in Patent 1,920,237, dated-August. l, 1933, to Clarence E. Beach and Foster E. Weld, for Signal Recorder.

Impulse sender contacts such-as those generally indicated'at 55, in Fig. 3, are here shownascomprising a flexible" contact 9! which ordinarily-- rests against the relatively fixed contacts 93 and; 95; Said contact ill is subject to actuation by the; Such actuator may be:

effecting momentary interruptions of the usualconnection between said contacts.-

A cover or can 55 (shown partly broken away in Fig. 3) is carried'by the inner side of the'door Zl, for the protection of the circuit conditioning contacts '55, H, Ti, Ill; l9 and the governing mechanism associated therewith.

Spring jacks such as those generally indicated at 8! and S3 in Fig. 6, are; carried by the inner door 22', for receiving plugs, such as may be assoclated with portable telephone sets. The portals G5 and ill of saidjacks are disposed behind the hood 89 shown in Figs. land'2, and are-thereindicated by dotted lines. The terminals of said, jacks project from-the rear side, of, the inner door 21, as indicated-at 3.8, inFig. 3.

The spring jack 8i is serially connected: between contact 95 and; one of the conditioning contacts 59, and jack 83' is serially connected" between fixed contact 93 and the other conditioning contact 79.

One of the conditioning, contacts II is con-- nected to the'ground (or'other common returnconductor), and the other of said contacts I! is connected to the fixed contact. 95.

The impulse sender contacts 9!, 93, and 95,

the Conditioning contacts l5, H, ll; '15, i9, and the spring jacks 8i, are shown associated with code transmitting mechanism (for the locationcode signal 23) schematically indicated at T in a fire alarm box case indicated by, the dotted line Si.

One of the terminals of the spring jack 8! (together with the associated one ofthe conditioning COIIBELCts l9, I9) is connected to one of the normally closed signal formulating contacts of the transmitter T. Another of the contacts of said transmitter is connected'tothe portion of the external cricuit leading toward the instruments EI and GI. The other sideof the external circuit (which leads toward the instrument LI) is connected to the other of the conditioning contacts l9 and to that terminal of the spring jack 83- which is associated therewith.

Another fire alarm boxor transmitting station S2 is shown connected in thecircuit between the :2.-

station Stand the responsive instruments EI, GI.

Th station S2 comprises transmitting mechanism schematically indicated at T for the location signal 2 i.

It will be understood that other stations may be similarly connected in the circuit at one side and the other of the station Si.

Operation, Figs. 1-6

Ordinarily, the outer door 23 and the cover il 6 are; closed:v The; boss. 43'; carried; by. the outendoor. then engages the. boss 4.1. carried-e Icy-the; cover for maintaining said cover. infully; closedr position. Such positioning of said Coven-acting through the camel and'the lever 63, causes the: cylinder 15. to rest against the contacts. 19 19'; as shown inFigp and indicated at c in'Figu 6-; thereby to establish a shunt path. for. the-fire alarm circuit around; the jacks 8i and.-.83;.andi around the signaling contacts 9! and'93. While. the parts are thus positioned; the currentipath. from contacttfi to the ground (or other common. return conductor) is interrupted at the contacts; ll, Th.

When. it .is. desired to send a special call, the: outer door. 23 should be opened, and the cover ll: should: be moved to open position, as. indie cated in Figs. 2 and 5. Such movement of Said-l cover ti will cause the cam. fil to act; through. the lever 63 to move the cylinder I5 outrof; engagement with the contacts l9; l9. andinto engagement with the contacts: H; l], as shown; in Fig. 5, and as also indicated by; dotted circlela. in Fig. 6.

Engagement of the contacts H, II, by the cylinder 75 at a time when the associated circuit is otherwise normally. conditioned, will establish parallel current paths as follows:

One of these pathsextends from a terminal of battery N5, through line signal manifesting: in.- strument LI, jack 83, contacts-93, 9i and 95, one of the contactsl'l, cylinder l5, the other contact "i'l', ground connection at the active signal sta tion and the earth, ground conncctionat central oflice, ground battery GB, to other terminal ofx battery NB;

The other parallel path extends from a terminal of battery GB through line signal manifesting instrument GI and rectifier IR (the path through line signal manifesting instrument -EI being blocked in this direction to current by the rectifier IR") from the rectifier. IR through signal station S2, throughclosed contacts of location-code transmitter T, through jack. iii, contacts 9i and 95, one of the contacts ll; cylinder '55, the other contact ll, thence-through station groundconnection and the earth to headquarters ground connection of other terminalof battery GB.

Establishment of these parallel paths will remder the instruments GI and LI responsive-to such signals as may be formulated by actuation of thecontacts 55 of station Si.

Such signal formulating actuation-of said contacts 55 may be accomplished by operation of the dial 5i in the manner corresponding to usual practice in making telephone calls with machines switching systems.

For example, if the call 238 is to be transmitted, the user will first place his finger in the opening numbered 2 in the dial 5!, and rotate the dial until his finger reaches the stop 53; He should thereupon remove his finger from the dial-and permit the mechanism to operate to formulate two signaling impulses in the parallel paths for causing response of the line signal manifesting instruments GI and LI. The dial 5i should then be correspondingly actuated to effect the formulation of signals 3 and 8.

Should one or the other of the parallel paths just referred to be ruptured or subjected to formulation of some other signal, continued eifectiveness of the other of such paths will, nevertheless, assure that the one of the instruments 1 GI, LI which is connectedin the .unimpairedlpathwill respond to signal formulated by the contacts 55, for reasons more fully explained in my aforementioned Patent No. 2,034,017.

For example, if the current path is broken at or adjacent the station S2, the actuation of the dial of station SI will not result in response of either the line signal manifesting instrument GI or the instrument EI. However, the instrument LI will respond to interruptions of the parallel current path first above described, incident to the action of the insulating actuator 91 in moving the contact 9i away from the contacts 93 and 95.

After completing use of the dial 5|, the cover E-I should be returned to its closed position.

If it is desired to connect a portable telephone set in the outside circuit, the cover 4i should be moved toward open position until the locating catch 99 engages the cooperating depression in the cam 8 I.

Such positioning of said cam will cause the cylinder E5 to be positioned as indicated by the dotted circle b in 6, where said cylinder is disengaged both from the contacts l9, l9, and the contacts l2, ll.

Such positioning of he cylinder Iii interrupts the normally effective shunt path around the jacks SI and 33, so that the entire line circuit will now traverse these jacks.

The telephone set plug may now be inserted in the portal of either of said jacks, and telephonic communication may then be effected, provided that the fire alarm circuit is unimpaired.

When a telephone se has thus been plugged into one of the jacks, if it is found that the circuit is open, the cover H should be moved toward or to its fully open position; thereby causing the cylinder 75 to move into engagement with the contacts 'li, Ti, and thereby establish a ground connection between said jacks SI and 83.

Following establishment of such ground connection, the unimp portion of the circuit may be found and utilized by inserting the telephone set plug in, say, jack GI and, if no current path is thus established, then inserting the plug in the other jack.

Thus, for example, if the line circuit is ruptured between stations Si and S2, plugging of a telephone set into a jack GI will not establish an effective circuit to the headquarters. However, if a telephone set is plugged into a jack 33, a circuit effective for telephonic communication will be established from a terminal of battery NB through line signal manifesting instrument LI, thence through jack and the telephone set plug therein, thence through contacts 83, 9! and 95, through one of the contacts ll, cylinder i5, and the other contact 5?, thence through the station ground connection and the earth to headquarters ground connection, through battery GB, and then to the other terminal of battery NB.

It should be noted that the location-code transmitters T and T shown in 6 are schematically indicated as being of the so-called closed circuit code wheel type (c. g., the circuit is momentarily broken for signal strokes, but is otherwise closed between strokes) and no noninterference feature is indicated at these stations; it being assumed that the ground connection at a given station is rendered effective throughout signaling activity of that station. However, embodiments of this invention such as otherwise shown by Fig. 6, may also be used in connection with transmitting stations having non-interference feature and open type code wheels such as 8 the mechanisms schematically indicated in Fig. 14 at Tn and Tn".

If the transmitting mechanisms at the signaling stations of the system of Fig. 6 have noninterference, succession, and emergency ground applying features such as provided by my aforementioned Patent No. 1,999,859, some confusion in manifestation of the signal of an active one of such stations may result from utilization of the special signal formulating facilities indicated in Fig. 6 in the manner hereinbefore set forth at a time when a location-code signal is being formulated. Although such confusion might be deemed unobjectionable in fire alarm'systems in which box circuit signals are received at a central office and from there retransmitted to the fire houses, the opportunity for such confusion is likely to be found objectionable where box circuit signals are received at the fire houses directly from the box circuits.

For example, assuming that the location-code transmitter at station S2 embodies a conventional type of non-interference mechanism, and is equipped with a so-called open circuit code wheel (e. g., the circuit being momentarily closed for signal strokes during signalling activity, but otherwise open between strokes) the opening of the cover ll of station Si, and the actuation of the dial 5! thereat, would not cause suspension of effective formulating activity at station S2, unless and until the circuit happened to be open at the contacts 9I, 93 at a time when the active transmitting mechanism attempted to close the circuit. Thus, the signal of station S2 would cause response of instrum nts EI and LI until the cover 4| of station SI is opened. Response of such instruments would be suspended while such cover is open, but instrument GI would respond to the insuing portion of the signal of station S2, while instrument LI would respond to the special call of station SI, and would be unaffected by the signal of the station S2 so long as the cover 'il remained open. However, were the signal of station S2 in course of formulation when the cover M of station SI is reclosed, instrument LI would thereafter respond to the remaining portion of the signal of station S2.

During the operating conditions outlined in the foregoing example, current paths would be established as follows:

During the formulation of the signaling station S2, prior to opening of the cover 4!, there would be a current path from one terminal of battery NB, through line signal manifestin instrument LI, to parallel current paths one of which includes one of the contacts 19, the cylinder 15 (the cylinder T5 being positioned as shown in Fig. 4), and the other contact 19; the other of which parallel paths includes the spring jack 83, the contacts 93 and SI, and the spring jack 85. From the junction between these parallel paths current would flow through the signal formulating contacts of station SI through the formulating contacts of station S2, and thence through the rectifier IR", and receiving line signal manifesting instrument EI; to the other terminal of battery NB; the alternative path through receiving instrument GI being blocked in this direction by the rectifier IR.

Opening of the cover lI results in positioning the cylinder 75 as indicated in Fig, 5 (as also indicated by dotted line 0 in Fig. 6) whereupon two parallel current paths will be provided from the battery GB, one of which paths includes the batcry NB, the instrument LI, the jack 83, the con- 9 tacts '93, 9| and as, one ofthe contacts '11, the cylinder '55, the other contact ll, the ground connection at station SI and the earth therefrom to the ground connection at the central office, and thence to the other terminal of battery GB.

The other parallel current path extends from said first named terminal to battery GB, through the instrument GI and .the rectifier IR (the alternative path through instrument EI being blocked in this direction by the rectifier IR") and from the rectifier IR, to the signal formulating contacts of station S2 and through these contacts to the ground connection at said station (the path from said contact to said ground connection'being established through the signaling activity as already explained) from the ground connection at stationSZ, through the earth and ground connection at central office to other terminal of battery GB.

From the foregoing, it will be evident that, after the cover M has been opened, the instrument LI will respond only to signals formulated by the contacts as, 9.! and S; and the instrument GI will respond only to signals formulated by the station S2.

It will further be evident that, upon subsequent closing of the cover it at station Si, the instrument LI will again be brought into responsive relationship to the formulating contacts of station-SZ.

Furthermore, if the location-code transmitters T and T were'both of the non-interference and open circuit code wheel type, the continuing signal from transmitter T might prevent the si nal of transmitter T from immediately following the special call which was sent while the cover 4! of station Si was open.

Description, Figs, 7-14 The embodiment oft-his invention indicated in Figs. 7 through 14 is specially suited for use in connection with transmitting stations having non-interference, succession and emergency ground applying features, although this embodiment might be advantageously used in connection with transmitting stations which are not equipped with the aforesaid features.

The principal differences between the embodiment of this invention shown by Figs. 1-6 (as thus far described in detail) and the embodiment shown by Figs. 7-14, are as follows:

The functions of the lever 63. are here divided between the levers 5t and 53', which carry the rollers "53 and I3", and the contact cylinders l5 and 75', respectively.

The rollers l3 and 13" are engaged by side by-side parts of the periphery of the cam portion 65.

The cam portion 6! has slots 6 and 5'1 formed in the respective sides thereof for receiving the rollers 73 and 73", respectively (see dotted lines Fig. 7).

Walls 69 and 68" at the inner side of said slots 6i and El provide continuations of the periphery of'the cam and the slot walls Ti and H provide internal camsurfaces for said rollers i3 and E3.

The parts are so proportioned that the cylinder i5 is spaced away from the contacts ii, "i'i when the cover il is fully closed, and engages said contacts when said cover is open at least until the catch es' is'effective (see Figs. 9, 1G, 12 and 13).

The proportioning of the parts is further such that said cylinder 15 engages said contacts l9,

79", onlywhen said cover 4! is-fully closed or is open not substantially more than to the extent which renders the catch 99 effective (see Figs. 8, 9, 11 and 12).

The impulse sender contacts 55 (see Figs. 7 and 14) comprise a flexible contact 98 which is ordinarily spaced away from the relatively fixed contacts 93 and 95. Said'con-tact '9! is subject to actuation by the insulating actuator 97' for effecting momentary closures between said contacts til, 93' and 'iifi.

By further reference to Fig, 14, it will be seen that the portion of the outside circuit which extends toward instrument LI is connectedto the portal terminal 3'? of jack 83, and that the flexible (or tip) terminal 88 of said jack is connected to the like terminal of jack 8i; while the portal terminal 85 of jack 8! is connected to signal formulating contact 93' and to the other hunting contact '19, Signal formulating contact st being connected to the transmitter Tn.

The jacks '85 and 83 are equipped with grounding contacts 85, 84, which contacts are so associated with the flexible contacts 85 and that when either of said flexible contacts is displaced by the insertion of an intended plus, such flexiblecontact will be brought into engagement with the associated grounding contact 3c, in addition to being moved away from the normally engaged shunting contact, as in the instance of jacks 8i and 83 of Fig. 6.

The formulating contact 9!, together with the jack'contacts M, 84, is connected to one of the flexible contacts Ti, and the other of said con tacts H is connected to the ground or other commonv return conductor.

Operation, Figs, 7-14 As in the case of the embodiment of this invention shown by Figs. 1-6, the outer door 23 and the cover 6! are normally closed; so that the cam 6i, acting through the levers 53 and 63" causes the cylinder 15 to be positioned away from the contacts H, H, and the cylinder It to be positioned in engagement with the contacts 3%,19 (see Figs. 8 and 11).

While the parts are thus positioned, there is a current path from a terminal to the battery NB, through line signal manifesting instrument LI, through jacks 83 and 8!, one of the contacts i3, cylinder '55 and the ,Other contact '59, through code signal formulating contacts of transmitters Tn and Tn, through rectifier IR and instrument E1, to the other terminal of battery NB; the path through instrument GI bein blocked to current in this direction by the rectifier IR.

Ifthe cover is moved to open position, as indicated in Fig. 10, the cam 6! will act through the lever 63 tomove the cylinder i5 into engagement withthe contacts ill, '5'! (thereby to prepare a ground path from formulating contact 9i and contacts 84, 84) and said cam 6! will further act through the lever 63 to carry the cylinder '55 away from the contacts I9, 19", thereby to interrupt the current path which ordinarily provides a shunt around the contacts 93, 95.

Is as much as the contacts es and 95' are ordinarily separated, interruption of the shunt around said contacts will open the associated outside circuit.

Assuming that all location-code transmitters (such as those exemplifiedat Tn, Tn) have 11 non-interference features, such interruption of the associated circuit will result in suspension of signal formulation by any such transmitter which may be active when the cover 4| is opened; and such suspension will be maintained until after said cover has been reclosed, other than in a contingency which will be hereinafter described in greater detail.

From the foregoing, it will be seen that actuation of the dial 5! (which can be accomplished only while the cover M is in open position) will cause a series of brief grounded circuit closures, resultant from actuation of the contact Q! by the actuator 9'! for the expression of the desired signal.

Parallel current paths will be established, incident to each of such grounded circuit closures, as follows:

One of said paths will extend from a terminal of battery GB, through the battery NB and a the line signal manifesting instrument LI, the spring jacks 83 and 8!, the contacts 93' and 9!, one of the contacts 11, the cylinder the other contact H and the ground connection at station Si, thence through the earth and the central ofiice ground connection to the other terminal of battery GB (the ordinarily established shunt around the contacts 9! and 95 being now interrupted, because of withdrawal of the cylinder '15 from between the contacts 19", T9") The other of said parallel paths extends from said first named terminal of battery GB, through line signal manifesting instrument GI and rectiiier IR (the current path through instrument EI being blocked in this direction by the rectifier IR) thence through code signal formulating contacts of transmitters Tn and Tn, through contacts 95 and SI, one of the contacts H, the cylinder '55, the other contact TI, the ground connection at station SI, thence through earth and central station ground connection to the other terminal of battery GB.

After a special call has been thus transmitted,

the location-code of the station to which response should be made can be transmitted by supplemental manipulation of the dial 5!, thereby assuring that such response will be to the desired location.

In this connection it should be noted that if the location-code transmitter of the same station were relied upon in such a case, there would be possibility that the corresponding transmitter of some other station would intervene, and

thereby cause misdirection of response which might have diastrous consequences.

For example, if a special call has been transmitted from station S l and the cover H is thereupon closed, and the starting handle of that station is then operated, there would be opportunity for a timely start to have been effected of the transmitting mechanism of station S2 such that it would prevent the signal of the transmitter Tn of station $5 from immediately following the special call, and thereby cause misdirection of response.

Furthermore, there are occasions when the 10- cation-code mechanism at a station is already acting at a, time when it is needful to send a special call therefrom. In such a case, opening of the cover ti of such station will result in suspension of the efiectiveness of the formulating action of uch transmitter, and will insure unimpaired response of the central station instruments (such as GI and LI) to the special call cover il 12 and to such location-code as may be supplementally transmitted by the dial 5|.

Should the outside circuit be ruptured at one side or the other of a station from which a special call is transmitted in the manner just explained, such call will nevertheless be responded to by whichever of the instruments GI or LI is associated with the portion of the circuit which is unimpaired.

There is possibility that a transmitting station (such as described by my aforementioned Patent No, 1,999,859) will apply its emergency ground connection and proceed with formulation of its location-code signal in the event that, while any is open, no signaling impulses are formulated from the dial 5| associated with such open cover for a time longer than that required for one revolution or round of the code wheel of such station. However, unless there is such an extended time of dial inactivity, such a station will not start or resume location-call formulation.

If it is desired to connect a portable telephone set in the circuit of an embodiment of this invention such as shown in Fig. 14, the plug associated with such set should be inserted in the portal of one or the other of the jacks 8!, 83'; whereupon telephone communication may be effected provided the exterior circuit is unimpaired. If, however, it is found that the circuit is open, when a seat is thus plugged in one jack or the other, the cover Al should be moved toward open position until the locating catch 99' engages the depression in the cam 6| provided for cooperation therewith.

The resultant positioning of said cam will cause the cylinder E5 to be moved into engagement with the contacts 2"], H, while leaving the cylinder 15" engaging the contacts ?9', '19 (see Figs. 9 and 12); thereby to prepare a ground connection with contacts 84, 84, while maintaining a shunt around the open formulating contacts 93, 95 through the shunting contacts 19', 19.

Following preparation of such ground connection, the unimpaired portion of the circuit may be found and utilized by inserting the plug in one jack after the other, until a current path is thereby established.

If circumstances of use are such that there is no occasion for utilizing portable telephone sets, the other features of this invention may be utilized without spring jacks (such as 8! and 83) Correspondingly, other features of this invention might, under certain circumstances, be advantageously used without the provision of a cover (such as the cover 4!) for the transmitter dial 5? manually operable facilities, other than said cover, being then provided for causing actuation of conditioning contacts.

While, in the foregoing, I have resorted to considerable detail of structure and association of parts in describing examples of my invention,

.; I wish it to be understood that I have done so merely to facilitate understanding of my invention and that I do not limit my invention to such details other than as set forth in the annexed claims. On the contrary, various changes and substitutions may be made, and parts may be added to or omitted from those I hereinbeiore described, without departing from the broader aspects of this invention.

It is also to be understood that the language used in the following claims is intended to cover 13 all of the generic and specific features of the invention herein described. and. all. statements of the scope of the invention, which, as a. matter of language, might besaid to fall therebetween.

What I claim and desire to secure by Letters Patent of the United States is:

l. A signal station including a signal box, a manually operable variable signal impulse-sender means including a dial in said box for selectively effecting formulations of diverse roups of code signaling impulses, a cover carried by said box positionable for obstructing manual operation of the dial of said sender means, conductors providing three circuits, said sender means includ-- ing signal .ormulating contacts responsive to actuation of said dial having connections with said circuits and adapted to govern interconnection therebetween, a switching means connected into said contacts and said circuits, and

means actuated by movement of the cover to different positions for in turn actuating the switching means to different positions, the connections between the ircuits and the switch ing means being effective when the cover is in.

an obstructive position with respect to the dial of the signal sender means for assuring interconnection between two of said circuits while isolating the third circuit therefrom, said switchingmeans including means effective when the cover is in an unobstructive position with respectto said dial for rendering interconnections between all three circuits dependent upon the closing of said formulating contacts.

2. A signal station as claimed in claim 1 characterized in that said signal formulating contacts are normally open, and said dial is a finger-hold dial.

3. A signal station including a signal box, a

' manually operable signal sendermeans'in said box for selectively effecting formulations of diverse groupsof code signaling impulses, a cover carried by said box positionable for obstructing manual operation of said signal sender means, conductors providing a normally closed main circuit and a normally isolated branch circuit, said sender means including normally closed signal formulating contacts having connections with said circuits and adapted to govern both the'continuity of said'main circuit and the interconnection of said branch circuit therewith, spring jacks serially connected'in said main circuit with at least one jack in each of portions of the oircuit at the respective sides of said contacts, a switching means connected into said circuits, and means actuated by movement of the cover to different positions for in turn actuating the switching means to different positions including the isolation of said branch circuit from said contacts, the connections between the circuits and the switchin means being effective for providing a shunt for the main circuit around said jacks and contacts when the coveris in an obstructive position with respect to the signal sender means, for interrupting said shunt when the cover is in an intermediate position, and for rendering continuity of said main circuit and interconnection of said branch circuit therewith dependent upon closures of said contacts only during unobstructive positionings of said cover with respect tosaid sender. means.

l. A signal station including a signal box, a manually operable signal. sender means in said box for selectively effecting formulations-of diverse groups of code signaling impulses, acover carried." by said box positionablefor obstructing manual operation of said signal sender means, conductors providing a normally closed maincircuit and'a normally isolated branch'circuit, said sender means including signal formulating contacts having"connectionswith said circuits and adapted to govern both the continuity of said main circuit. and the interconnection of said branch. circuit therewith, spring jacks serially connected in said-main circuit, a:switching means connectedinto' said circuits-, means-actuated, by movement of the cover to different positions for in turn actuating the switching means to difierent positions, the connections between the circuits and: the switching means being effective only when the cover is in an unobstructive position with'respect to the signal sender means for th interconnection of the branch circuit either through said formulating contacts or through said jacks. and means for yieldably retaining said cover in an intermediate position for effecting circuit conditions differing from those established either during fully obstruotiveor fully unobstructive positionings of said cover with respect'to said signal sender means.

5. A signal station including a signal box, a manually operable signal sender means in said box for selectively effecting formulations of diverse groups of code signalling impulses, a cover carried by said box positionable for obstructing manual operation of said signal sender means, conductors providing a normally closed main circuit and a normally isolated branch circuit. said signal sender means including normally open signal formulating contacts having connections with said circuits and adapted to govern both the continuity of said main circuit and the interconnection ofsaid branch circuit therewith, spring jacks each comprising a pair of normally engaged contacts and a third contact normally separated therefrom; one of the contacts of said pair being adapted to be moved away from the other contact of said pair and into engagement with said third contact upon the insertion of a plug into the jack, conductors serially connecting two of said signal formulating contacts and the normally engaged contacts of said jacks in said main circuit, a switching means connected into said circuits, and means actuated by movement of the cover to different positions for in turn actuating the switching means to different positions, the switching means including means for connecting said branch circuit both with said signal formulating contacts and with said third contacts of the jacksonly during unobstructive positionings of said cover with respect to said signal sender means and for providing a shunt for said main circuit around signal formulating contacts only during fully obstructive positioning and during an intermediate positioning of said cover with respect to said signal sender means.

6. A signal station including a signal box, a manually operable signal sender means in said box for selectively efiecting formulations of dition of said branch circuit therewith, spring jacks serially connected in said main circuit, a switching means connected into said circuits, and means actuated by movement of the cover to diilerent positions for in turn actuating the switching means to different positions, the connections between the branch circuit and the switching means being effective for the interconnection of the branch circuit either through said formulating contacts or through said jacks only when the cover is in an unobstructive position with respect to the signal sender means.

7. A signal station including a signal box, a manually operable signal sender means in said box for selectively effecting formulations of diverse groups of code signaling impulses, a cover carried by said box positionable for obstructing manual operation of said signal sender means, conductors providing a normally closed main circuit and a normally isolated branch circuit, said signal sender means including a finger hold dial and normally closed signal formulating contacts having connections with said circuits and adapted to govern both the continu ty of said main circuit and the interconnection of said; branch circuit therewith, said signal formulating contacts being responsive to the actuation of said d-al, spring jacks serially connected in said main circuit with at least one jack in each of portions of the circuit at the respective sides of said contacts, a switching means connected into said circuits, and means actuated by movement of the cover to different pos'tions for in turn actuating the switching means to diiferent positions, the connections between the circuits and the switch ing means being effective for isolating said branch circuit from said contacts and for providing shunt for the main circuit around said jacks and contacts when the cover is in an obstructive position with respect to the signal sender means, for interrupting said shunt when the cover is in an intermediate position and for rendering continuity of said main circuit and interconnection of said branch circuit therewith dependent upon closures of said contacts only during unobstructive positionings of said cover with respect to said sender means.

8. A signal station including a signal box, a manually operable signal sender means in said box for selectively effecting formulations of diverse groups of code signaling impulses, a cover carried by said box positionable for obstructing manual operation of said signal sender means, conductors providing a normally closed main circuit and a normally isolated branch circuit, said sender means including impulse formulating contacts having connections with said circuits and adapted to govern both the continuity of said main circuit and the interconnection of said branch circuit therewith, spring jacks serially connected in said main circuit, a switching means connected into said circuits, means actuated by movement of the cover to different positions for in turn actuating the switching means to different positions, the connections between the circuits and the switchin means being effective for the interconnection of the branch circuit either through said formulating contacts or through said jacks when the cover is in an unobstructive position with respect to the signal sender means and for providing a shunt for the main circuit around said contacts when the cover is in an obstructive position with respect to the signal sender means, and means for yieldably Cir 16 retaining said cover in an intermediate position for effecting circuit conditions differing irom those established either during fully obstructive or fully unobstructive positicnings of said cover with respect to said signal sender means.

9. A signal station including a signal box, a manually operable signal sender means in said box for selectively effecting formulations of diverse groups of code signaling impulses, a cover carried by said box positionable for obstructing manual operation of said signal sender means, conductors providing a normally closed main circuit and a normally isolated branch circuit, said signal sender means including normally closed signal formulating contacts having connections with said circuits and adapted to govern both the continuity of said main circuit and the interconnection of said branch circuit therewith, spring jacks serially connected in said main circuit with at least one jack in each of portions of the circuit at the respective sides of said contacts, a switching, means connected into said circuits, means actuated by movement of the cover to different positions for in turn actuating the switching means to difierent positions, the connections between the circuits and the switching means being efiective for isolating said branch circuit from said contacts and for providing a shunt for the main circuit around said jacks and contacts when the cover is in an obstructive position with respect to the signal sender means, for interrupting said shunt when the cover is in an intermediate poition, and for rendering continuity of said main circuit and interconnection of said branch circuit therewith dependent upon closures of said contacts only during unobstructive positionings of said cover with respect to said sender means, and means for yieldably locating and retaining said cover in said intermediate position.

19. A signal station including a signal box having an outer door and an inner door, a signal sender means including a finger hold dial mounted upon the outer side of said inner door, conductors providing a normally closed main circuit and a normally isolated branch circuit, said signal sender means including signal formulating contacts located inside the inner door and having connections with said circuits and adapted to govern both the continuity of said main circuit and the interconnection of said branch circuit therewith, said signal formulating contacts being responsive to the actuation of said dial for selectivel effecting formulations of diverse groups of code signaling impulses, a cover hinged to the outer side of said inner door and positionable for obstructing manual operation of said dial, spring jacks serially connected in said main circuit carried by said inner door and accessible from the outer side thereof, a switching means connected into said circuits, means actuated by movement of the cover to difierent positions for in turn actuating the switching means to different positions, the connections between the circuits and the switching means being effective for the interconnection of the bran-ch circuit either through said formulatin contacts or through said jacks but only when the cover is in an unobstructive position with respect to said dial and for effecting circuit conditionings differing from those estab lished either during fully obstructive or fully unobstructive positionings of the cover with respect to the dial when the cover is in an intermediate position, means for yieldably retaining said cover in an intermediate position, and means cooperating with said cover and said outer door for insuring fully obstructive positioning of said cover when the outer door is closed.

CLARENCE E. BEACH.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date Feller Oct. 27, 1914 Number 18 Name Date Detmers Mar. 23, 1926 Philbrick Dec. '7, 1926 Carnahan Mar. 12, 1929 Carl Aug. 8, 1933 Carl Dec. 10, 1935 Beach Mar. 17, 1936 McCarthy Sept. 22, 1936 

